I like to back in, but most of the shopping centers around here have the angled parking spaces with the up and down aisles. If you backed in, when you pull out, you'll be going the wrong way. And, I won't back in if there's someone behind me because they'd be waiting on me and that feels rude.
My dad says he does what ever is easier at the time. But I have a thing with parking. I always back in unless i cant for some reason. My girlfriend is the worst driver lol i have to back her car up all time. I always use my mirrors.